Suspended centrifugal apparatus



April 12, 1960 D. M. THOLL SUSPENDED CENTRIFUGAL APPARATUS 3Sheets-Sheet 1 Filed June 13, 1957 April 12, 960 D. M. THOLL 2,932,401

USPENDED CENTRIFUGAL APPARATUS Filed June 13, 1957 3 Sheets-Sheet 2 ll il 5? 42 i 71 x 6 I 8 I 7 I I 1 L i I L i Z0 1 f 2 i i l' v A; H I I I, i

lnveaaiow PM me L l l i I SUSPENDED CENTRIFUGAL APPARATUS David M.Tholl, Needham, Mass., assignor to American Tool & Machine Company,Boston, Mass, a corporation of Massachusetts Application June 13, 1957,Serial No. 665,564

6 Claims. (Cl. 210-369) This invention relates to a suspension typecentrifugal for use in centrifugally separating fluid from variousmaterials and, in particular, the invention is concerned with acentrifugal for removing washwater from relatively light, bulky productssuch as leafy vegetables and the like.

In dealing with a product such as leafy vegetables, and

nited States Fatent O V which a fluid may be expelled when the basketload is subjected to centrifugal forces.

At its upper side, the basket is open to admit material to becentrifuged which may, for example, be delivered from a conveyor member24 (Fig. 1).

In accordance with the best form of the invention, 1

7 provide in the basket 22 a special adjustable bottom in particularspinach, the need is for a type of centrifugal which can quickly andcheaply carry out a separation of wash water from the spinach and thendischarge the centrifuged product with a minimum of interference orsticking of the washed product to the basket. In addition, it isimportant to provide a type of discharge which can be used eifectivelywith automatic control means as well as loading and discharge conveyordevices.

To meet these requirements, I have devised a centrifugal constructionwhich is based on the novel concept of combining a centrifugally drivenbasket with a vertically adjustable bottom mechanism and supporting boththese structures from a suspension drive which revolves about avertically adjustable axis. I have discovered that this novel conceptmay be practically realized by utilizing .a telescopic arrangement ofparts whereby a conical bot- .tom element and lift rod is adapted tomove into a lowered discharge position in response to forces of gravity..However, when actuated by a positive fluid pressure, the .conicalbottom and lift rod may be raised into a closed .or sealed position. Animmediate advantage which is derived from this type of assembly is thatboth the cenatrifugal drive for the basket and the actuating means forproducing fluid pressure can be mounted in a common supporting structureat the top of the centrifugal machine frame.

These and other objects, novel features and advantages will be morefully understood and appreciated from the following description ofpreferred embodiments of the invention selected for purposes ofillustration and shown in the accompanying drawings in which:

Fig. l is a view in front elevation of the centrifugal of the inventionillustrating the basket and vertically movable bottom in closed relationto one another and further indicating in dotted lines the bottom loweredinto a discharge position;

Fig. 2 is a view in side elevation of the structure shown in Fig. 1;

Fig. 3 is a detail cross-sectional view; and

Fig. 4 is an enlarged vertical cross-sectional view of the suspensiondrive and the actuating means for raising and lowering the basket.

Referring more in detail to the drawings, numerals 2 and 4 indicateupright members of one suitable frame structure of the invention. At theupper side of this frame structure are transversely extending channelmembers as 6 and 8 bolted together and resting on other channel membersas 10, 11, 12 and 13. At intermediate portions of the upright'members 2and 4 are secured angle brackets as 14 and 16, as shown in Fig. 1,

section which can be dropped down to furnish a discharge outlet. Thisbottom section preferably consists of a conically shaped member 26, suchas. that shown in Fig. 1. This conically shaped member is constructed atits lower side with a beveled seating surface adapted to seat against anupturned edge 27 which is formed at the lower edge of the basket 22.

In combination with this movable bottom section 26, I further provide aspecial actuating device for raising and lowering this conical bottomsection 26. An unusual feature of the actuating device is that it isdesigned to form a part of a suspension drive mechanism shown on anenlarged scale in Fig. 4. An important element of the actuating deviceis a lift rod element 28 which, at its lower end, is connected to thetop of the conically shaped member, as shown in Fig. 1.

In a preferred form of the invention, I mount the lift rod 28 intelescoping relationship within a tubular drive shaft element 32 of thesuspension drive mechanism. The upper portion of the lift rod passesthrough a tubular shaft extension 32a and extends into the bore 34 of apulley 38 fixed on the element 32a, as suggested in Fig. 4. Threaded orotherwise secured to the upper end of the lift rod 28 is a piston rod 38carrying a plunger 40. The plunger 40 is mounted in sealing relationshipwithin a cylinder 42 which is bolted to the upper side of the pulley 36on a suitable base plate 44.

By means of the arrangements of parts described, it

. will be apparent that the lift rod and conical bottom 26 are free todrop downwardly in response to forces of gravity into the broken lineposition indicated in Fig. 1. To raise the unit,'in accordance with theinvention, there is provided at the bottom of the cylinder 42 a tubularconduit 48 connected through the side wall of this member. The upper endof the tubular conduit 48 is also connected to an air supply conduit 50by means of a suitable fitting and compressed air is delivered through arotary sealerunit 52 and mounting pipes 54 and 56 from a sourcecontrolled by a conventional type four-way air valve unit 54.

When the air valve is opened at a desired point, air or other compressedfluid flows through the member 48 into the bottom of a closed space inthe cylinder 42 and the piston is forced upwardly into the positionshown in Fig. 4, carrying the conical bottom 26 into sealed relationshipto the bottom of the basket 22. To facilitate this movement of thepiston and release of air, I may provide a bleeder valve 60 at therupper end of cylinder 42 (Fig. 4). As earlier noted, an importantfeature of the conical bottom section 26 and the actuating device abovedescribed is its attachment to the suspension drive so that it mayrevolve with the tubular drive shaft when the latter is rotated.

As shown in Fig. 4, the tubular extension 32a is provided with cuppedbearing means 62 mounted in a bearing plate 64 bolted to the transverseframe members 6. Threaded expansion member 66 is tightly engaged againsta sealing member 68 which rests against conical seat 76'. A motor 72actuates pulleys 76 through a reduction gear mechanism 74 to drive thepulley and shaft 32 which in turn drives the basket together with theconical bottom section and lift rod.

It is pointed out that, by means of this arrangement, the basket may bedriven at varying speeds and at any desired point, the conical bottommay be raised or lowered as required while the machine is running. Imay, in this connection, also employ a standard type of air brakingmechanism indicated in the drawings at 78 for releasing or tightening abrake band element 80 located around a brake drum portion 82 fast on thetubular member 32.

The braking mechanism may be actuated automatically by means of aconventional air cylinder or other suitable control.

As shown in Fig. 1, material may be delivered to the basket from theconveyor 24. A second conveyor 84 is located in a suitable positionbelow the basket to receive and carry away centrifuged material which isdischarged from the basket when the conical bottom section 26 is allowedto drop into its lowermost position. A hopper 86 with a convergingbottom aperture may be employed to guide the discharged material on tothe conveyor 84.

In the case of certain types of materials it may also be desired toprovide means for mechanically scraping the inner peripheral surface ofthe basket 22 in order to dislodge material collecting thereon. As onesuitable means of accomplishing this, I have combined with the movablebottom section 26 described above a special discharger shoe 90 which, asshown in Fig. 1, may be supported on uprights 92 and 94 fixed to thebottom section. This discharger shoe is of annular form and presents arolled edge adapted to lightly engage against the basket peripheryaround the top thereof and, when the conical bottom 26 is allowed todrop downwards, the discharger shoe also drops and carries with itcollected material. If desired, I may also use compressed air or otherfluid to positively force the scraper downwardly.

In a typical operating cycle, the air cylinder is actuated to raise theconical section 26 into a sealed position and the basket is rotatablydriven to bring it up to a speed of about rpm. The basket is held atthis speed for a short interval to provide for loading. Thereafter, thebasket speed is increased to a predetermined proper extracting speed andcontinued at this speed while centrifuging is carried out. Thereafter,the power is cut off automatically and the brake applied and the conicalbottom section 26 is allowed to drop down to permit discharge of thecentrifuged material which is automatically conveyed to a desired point.If desired, the air operated piston may be positively forced down insome cases.

It is again pointed out that the lift rod and conical bottom section,together with the basket 22 and cylinder 42, all revolve as a singleunit during the centrifuging cycle with the tubular member 50 revolvingin the rotary sealing unit 52 in the well-known manner. It will beevident that, by thus driving the basket with a suspension drive andallowing the conical bottom to be raised and lowered through thissuspension drive, it becomes possible to eliminate separate actuatingmechanisms at points below the basket and this, in turn, facilitates theuse of a discharge and conveyor for centrifuged material. It will alsobe seen that, by the telescoping arrangement of parts described, the useof automation is greatly facilitated and the entire loading cycle,centrifuging cycle'and discharge cycle may all be set to operateautomatically in a desired sequence with a single control agency.Moreover, a simplified construction is made possible with a much smallernumber of parts being necessary.

It will be understood that various changes and modifications may beresorted to within the scope of the appended claims.

Having thus described my invention, what I claim is:

1. An improved centrifugal comprising a frame having a curb supportedthereon, a suspension drive mechanism, including a tubular drive shaftand concentrically located lifting means, a cylindrical basket elementfixed to the lower end of the tubular drive shaft, said cylindricalbasket having a vertically adjustable conical bottom attached to thelifting means, said conical bottom having a diameter at least equal tothe inner diameter of the basket, power driven means for rotating saidtubular drive mechanism and basket thereby to compress an annular massof centrifuged material into adhering relationship with respect to theinner peripheral surface of the basket, and said lifting means beingaxially displaceable in said drive mechanism for lowering the verticallyadjustable conical bottom out of seated relationship with respect to thebasket to define an unobstructed cylindrical aperture of the samediameter as the inner diameter of the basket whereby the adheringannular mass of centrifuged material is free to drop away from thebasket without interference.

2. A structure as defined in claim 1 in which the axially displaceablelifting means includes a cylinder, a piston and piston rod mounted forreciprocating movement in the cylinder, said piston rod at its lower endbeing connected to the vertically adjustable bottom, and fluid pressuremeans for acting on the piston and raising the vertically displaceablebottom into seated relationship when the basket is to be employed inholding a material to be centrifuged.

3. A structure according to claim 2 including a source of compressedfluid, a rotary sealer unit and a conduit element connected between thesource of compressed fluid and the said piston and cylinder whereby thelatter elements are supported for rotation with the basket.

4. A structure according to claim 3 including discha'rger shoe meansattached to the adjustable bottom for dislodg'ing material from thebasket.

5. A structure according to claim 1 including vertical supporting armsfixed to the adjustable bottom and an annular discharger element mountedon the supporting arms in a position to engage and remove material fromthe inner periphery of the basket.

6. A structure according to claim 1 including air cylinder means forautomatically controlling the axially displaceable means.

References Cited in the file of this patent UNITED STATES PATENTS

